Viral infections, in addition to damaging host cells, can compromise the host immune system, leading to frequent relapse or long-term persistence. Viruses have the capacity to destroy the host cell while liberating their own RNA or DNA in order to replicate within additional host cells. The viral life cycle makes it challenging to develop anti-viral drugs. Nanotechnology-based approaches have been suggested to deal effectively with viral diseases, and overcome some limitations of anti-viral drugs. Nanotechnology has enabled scientists to overcome the challenges of solubility and toxicity of anti-viral drugs, and can enhance their selectivity towards viruses and virally infected cells, while preserving healthy host cells. Chitosan is a naturally occurring polymer that has been used to construct nanoparticles (NPs), which are biocompatible, biodegradable, less toxic, easy to prepare, and can function as effective drug delivery systems (DDSs). Furthermore, chitosan is Generally Recognized as Safe (GRAS) by the US Food and Drug Administration (U.S. FDA). Chitosan NPs have been used in drug delivery by the oral, ocular, pulmonary, nasal, mucosal, buccal, or vaginal routes. They have also been studied for gene delivery, vaccine delivery, and advanced cancer therapy. Multiple lines of evidence suggest that chitosan NPs could be used as new therapeutic tools against viral infections. In this review we summarize reports concerning the therapeutic potential of chitosan NPs against various viral infections.

Over the years, conventional cancer treatments, such as chemotherapy with only a limited specificity for tumors, have undergone significant improvement. Moreover, newer therapies such as immunotherapy have undergone a revolution to stimulate the innate as well as adaptive immune responses against the tumor. However, it has been found that tumors can be selectively colonized by certain bacteria, where they can proliferate, and exert direct oncolytic effects as well as stimulating the immune system. Bacterial-mediated cancer therapy (BMCT) is now one example of a hot topic in the antitumor field. Salmonella typhimurium is a Gram-negative species that generally causes self-limiting gastroenteritis in humans. This species has been designed and engineered in order to be used in cancer-targeted therapeutics. S. typhimurium can be used in combination with other treatments such as chemotherapy or radiotherapy for synergistic modification of the tumor microenvironment. Considerable benefits have been shown by using engineered attenuated strains for the diagnosis and treatment of tumors. Some of these treatment approaches have received FDA approval for early-phase clinical trials. This review summarizes the use of Salmonella bacteria for cancer therapy, which could pave the way towards routine clinical application. The benefits of this therapy include an automatic self-targeting ability, and the possibility of genetic manipulation to produce newly engineered attenuated strains. Nevertheless, Salmonella-mediated anticancer therapy has not yet been clinically established, and requires more research before its use in cancer treatment.

ObjectivesTuberculosis remains one of the top three infectious disease killers. The prevalence of multidrug-resistant tuberculosis (MDR-TB) has increased substantially in the past 20 years. When drug resistance is not detected, MDR-TB patients cannot access life-saving treatment; this puts their communities at risk of ongoing MDR-TB transmission. We aimed to determine the patterns of resistance to antituberculosis drugs among Mycobacterium tuberculosis isolates from Khuzestan province in Iran.MethodsA total of 850 clinical specimens from patients suspected of active TB were cultured in 2015. Drug susceptibility testing to the first line antiTB drugs for culture positive MTB was performed on Lowenstein–Jensen medium using the proportion method.ResultsOf 850 cultured specimens, 272 (32%) were culture positive for mycobacteria. Of 64 MTB isolates that were analyzed by the proportion method, 62 (96.8%) were pan-susceptible and two (3.1%) were MDR.ConclusionAn important way to prevent the emergence of MDR and XDR TB, and the principles of full implementation of the strategy is directly observed treatment, short-course (DOTS). The efficient diagnosis and timely treatment of MDR-TB patients can prevent disease transmission, reduce the risk of drug resistance developing, and avoid further lung damage.

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Background: Recent studies have shown an increasing incidence of antibiotic resistance in dacryocystitis. Management of diseases may include determining microbial agents and choosing appropriate antibiotics for treatment. Objectives: This study aimed to present the best treatments for dacryocystitis. To this end, specimens' microbiology and antibiotic susceptibility were examined in patients with dacryocystitis in the microbiology laboratory of the Kashan University of Medical Sciences. Methods: This cross-sectional study was performed on 172 patients presenting with acute and chronic dacryocystitis at the Matini Hospital, Kashan, between 2017 - 2018. Patient characteristics, culture isolates, and antimicrobial susceptibility data were collected. The PCR assay of the mecA gene was performed in all methicillin-resistant Staphylococcus isolates. Results: The most common bacteria were coagulase-negative staphylococci, Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii. The majority of the isolated microbes were sensitive to rifampicin, linezolid, amikacin, and gentamicin. In Gram-negative bacilli, nine of the isolates were extended-spectrum beta-lactamase positive. The PCR test showed the frequency of mecA gene of resistant S. aureus and resistant coagulase-negative staphylococci (CoNS) isolates to be 40 and 46.3%, respectively. Conclusions: CoNS were the most frequently isolated bacteria. The highest antibiotic susceptibility was observed to rifampin, linezolid, amikacin, and gentamicin. A high percentage of CoNS carried the mecA gene.